共沉淀镍催化剂用于膜反应器中高碳烃类燃料水蒸气重整反应

 采用共沉淀法制备了NiO/La-Al2O3催化剂,利用低温N2物理吸附、程序升温还原、 H2-O2化学吸附和X射线衍射对催化剂进行了表征,并将该催化剂应用于Pd膜反应器中高碳烃类燃料水蒸气重整反应. 结果表明,催化剂中NiO与载体间存在较强的相互作用. 与常规固定床反应器相比,在膜反应器中,由于高渗透性能的Pd金属复合膜能选择分离氢气,结果氢气产率得到了明显的提高,甲烷的生成得到了有效抑制,并且在接近实用的反应条件下,依然能够得到高的氢气产率和回收率. 高碳烃类燃料水蒸气重整反应制氢的过程可以在一个膜反应器中,利用一种催化剂在反应温度低于823 K的温和条件下实现.

Application of Coprecipitated Nickel Catalyst to Steam Reforming of Higher Hydrocarbons in Membrane Reactor

The Ni/La-Al_2O_3 catalyst prepared by a coprecipitation method was employed to hydrogen production from steam reforming of higher hydrocarbons in a palladium membrane reactor.The catalyst was characterized by low temperature N_2 adsorption,H_2 temperature-programmed reduction,H_2-O_2 chemisorption,and X-ray diffraction.The results showed that there was a strong interaction between NiO and the support.In the Pd membrane reactor,due to the selective removal of H_2 by the membrane,the yield of H_2 was increased significantly,while the formation of methane was suppressed in contrast with the results in the conventional fixed-bed reactor.Even under the near-practical application conditions,e.g.,high GHSV and small flux of sweep gas,high yield of H_2 and membrane separation efficiency were still obtained.Furthermore,no degradation of the membrane was observed even under working conditions of 823 K and steam-to-carbon feed ratio 2.7.This suggested that it was feasible to realize H_2 production from steam reforming of higher hydrocarbons using only one reactor and one nickel-based reforming catalyst at reaction temperatures lower than 823 K.